Zone 3 Planting Calendar: What to Plant and When

Winter lows of -40 to -30F and a growing season that often runs only 90 to 120 days put Zone 3 near the cold edge of what is possible in the continental United States. Gardeners here work with a narrow window: the ground stays frozen well into spring, the last frost can hold off until early June, and the first fall frost can arrive in early September. That is still enough season for a real harvest, as long as the warm-season crops are already several weeks old in a tray by the time the soil is ready. This Zone 3 planting calendar lays out the whole year month by month, so nothing waits on the windowsill a week too long.

Zone 3 planting calendar

Use this month-by-month Zone 3 planting schedule as your season map. It shows when to start seeds indoors, when to move transplants outside, what you can direct sow, and what should be ready to harvest. Dates shift with the weather each year, so pair it with your local last and first frost dates from the ZIP code planting calendar.

Zone 3 planting schedule at a glance

The Zone 3 year runs like this. From late January through March you start seeds indoors under lights, beginning with onions, leeks, and celery and moving on to peppers, cabbage, and tomatoes. Direct sowing of peas, spinach, and radish begins as soon as the soil is workable, usually in April, and tender crops only go out after the last frost passes in late May or early June. The main harvest runs from July through September, and the fall sowings of spinach, lettuce, and arugula go in during August, with garlic and cover crop following in September and October.

A dash means there is little to plant or harvest that month in Zone 3. Cold months are for planning, ordering seed, and starting the earliest crops indoors under lights.

The best crops for Zone 3

The most reliable Zone 3 vegetables are cold-hardy and quick to mature, the kind that handle a short, cool season and even shrug off a light frost. Lean on these and you will fill your beds with far less risk:

Vegetables

• Leafy greens and lettuce. Lettuce, spinach, and kale are fast, frost-tolerant, and happy in the cool ends of the season. Browse lettuce seeds, spinach seeds, and kale seeds.
• Root crops. Carrots, beets, and radishes mature quickly and store well. See carrot seeds, beet seeds, and radish seeds.
• Peas and beans. Peas love the cool shoulder seasons, and bush beans give a fast summer crop. Try pea seeds and bean seeds.
• Brassicas. Broccoli, cabbage, and their cousins thrive in the cool weather this zone does best. Explore broccoli seeds and cabbage seeds.
• Warm-season crops, started early. Tomatoes and peppers ripen in Zone 3 if you start seeds indoors 6 to 8 weeks before the last frost and choose shorter-season varieties. See tomato seeds and pepper seeds.

Herbs and flowers

Hardy herbs like chives, dill, parsley, and cilantro do well in Zone 3, and cheerful cold-tolerant flowers such as calendula, nasturtium, and sunflowers add color and pull in pollinators. Start with our herb seeds, and for the full range see all of our vegetable seeds.

When are the frost dates in Zone 3?

Your last spring frost is the average date of the final freeze before summer, and your first fall frost is the average date of the first freeze after it. In Zone 3 the last frost typically falls around late May to early June and the first fall frost around early to mid September, leaving a growing season of about 90 to 120 days. Those two dates drive everything: you start most warm-season seeds indoors weeks before the last frost, plant tender crops out only after it, and count backward from the first fall frost to know how late you can sow.

These are averages for the whole zone, and your yard can run a week or two earlier or later. For the exact last and first frost dates at your location, enter your ZIP code in our interactive planting calendar and plan your Zone 3 garden around your real local dates.

Zone 3a vs 3b: last and first frost dates

Zone 3 is split into two half-zones that sit about 5F apart. Zone 3a is the colder half, Zone 3b the milder one, and that small difference in winter low tracks a real difference in the season: a 3b gardener is typically a week or two ahead of a 3a gardener in spring and hangs on a week or two longer in fall. Both halves fall inside the zone-wide window of around late May to early June for the last frost and around early to mid September for the first one, but they sit at opposite ends of it.

In practice that means 3a gardeners plan for the short end of the range and lean harder on transplants, while 3b gardeners can direct sow a little earlier and still finish a longer-season crop. Either way you start seeds indoors on the same principle, counting backward from your own last frost rather than the zone average. Elevation, a nearby lake, a sheltered south wall, or a low frost-pocket in the yard will move these dates by weeks, so treat the table below as the starting point and confirm your local dates with the ZIP code planting calendar.

What does USDA Zone 3 mean?

USDA Plant Hardiness Zones are based on the average annual coldest winter temperature. Zone 3 means your average extreme winter low lands between -40 to -30F. That number tells you which perennials, shrubs, and trees can survive the winter in the ground, so it is a measure of winter hardiness, not frost dates or season length. When a plant is labeled hardy to Zone 3, it means the plant can normally live through a Zone 3 winter. For annual vegetables you plant fresh each spring, your frost dates and season length matter more than the hardiness number, which is why this calendar leans on both.

Not sure this is your zone? If your winters are colder, see our Zone 2b planting calendar. If they are milder, check the Zone 4 planting calendar. And for your exact dates, always confirm with the ZIP code planting calendar.